tailieunhanh - Báo cáo lâm nghiệp: "Multiscale computation of solar radiation for predictive vegetation modelling"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Multiscale computation of solar radiation for predictive vegetation modelling. | Ann. For. Sci. 64 2007 899-909 Available online at INRA EDP Sciences 2007 DOI forest 2007072 Original article Multiscale computation of solar radiation for predictive vegetation modelling Christian PlEDALLU Jean-Claude GÉGOUT AgroparisTech-ENGREF LERFoB UMR INRA-ENGREF 1092 - Équipe Écologie Forestière 14 rue Girardet 54042 Nancy Cedex France Received 12 February 2007 revised version 29 May 2007 accepted 4 July 2007 Abstract - The recent development of large environmental databases allow the analysis of the ecological behaviour of species or communities over large territories. Solar radiation is a fundamental component of ecological processes but is poorly used at this scale due to the lack of available data. Here we present a GIS program allowing to calculate solar radiation as well locally as at large scale taking into account both topographical slope aspect altitude shadowing and global cloudiness and latitude parameters. This model was applied to the whole of France 540 000 km2 for each month of the year using only a 50-m digital elevation model DEM latitude values and cloudiness data. Solar radiation measured from 88 meteorological stations used for validation indicated a R1 of between measured and predicted annual radiation with better predictions for winter than for summer. Radiation values increase with altitude and with slope for southern exposure excepted in summer. They decrease with latitude nebulosity and slope for north east and west exposures. The effect of cloudiness is important and reduces radiation by around 20 in winter and 10 in summer. Models of plant distribution were calculated for Abies alba Acer pseudoplatanus and Quercus pubescens for France. The use of solar radiation improved modelling for the three species models directly or through the water balance variable. We conclude that models which incorporates both topographical and global variability of solar radiation can improve efficiency of large-scale .